Linear Table Structure

ABSTRACT

A linear table structure comprises a groove body, a first screw, a second screw, two sliding seats, and a connecting calibrating assembly. One end of the first screw and that of the second screw are connected and supported by the connecting calibrating assembly, and the positioning portion of the connecting calibrating assembly is used to adjust the pitch error generated on the first and second screws by the sliding seats, thus reducing machining time and cost.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a table structure, and moreparticularly to a linear table structure.

2. Description of the Prior Art

A conventional double sliding-seat linear table 10 (as shown in FIG. 1)serves as a holding and positioning device and comprises a groove body11, a screw 12, and two sliding seats 13.

The groove body 11 is defined with a receiving space 111. A firstthreaded section 121 and a second threaded section 122 are coaxially andsymmetrically formed on the outer surface at both ends of the screw 12.Both ends of the screw 12 are pivotally connected to the opposite innersurfaces of the receiving space 111 of the groove body 11. Each of thesliding seats 13 is disposed at its bottom with two nuts 131 throughwhich the sliding seats 13 are fixed to the first and second threadedsections 121 and 122, respectively. The nuts 131 of the sliding seats 13are meshed with the clockwise thread of the first threaded section 121and the counterclockwise thread of the second thread section 122, suchthat when the screw 12 rotates, the nuts 131 will drive the two slidingseats 13 to move relative to each other. However, this conventionallinear table has the following disadvantages:

First, the first threaded section 121 and the second threaded section122 are coaxially and symmetrically formed on the single screw 12 byprecision machining, and the precision machining is cost intensive andtime consuming.

Second, the positions of the threads machined on the nut 131 of thesliding seats 13 are different, therefore, it is impossible to controlthe relative position of the two sliding seats 13 accurately. Plus thesingle-screw machining is unable to provide displacement tolerance forcalibrating the sliding seats 13, thus the calibration difficulty isrelatively increased, and when doing calibrating operation, it needs anadditional adjustment mechanism, thus increasing the cost.

Third, since it is pivotally disposed in the receiving space 111 of thegroove body 11, the screw 12 is likely to oscillate during rotation. Thelength of the screw 12 is determined by the degree of oscillation, andif the screw 12 oscillates too violently, it will severely affect theprecision of the displacement of the sliding seats 13.

The present invention has arisen to mitigate and/or obviate theafore-described disadvantages.

SUMMARY OF THE INVENTION

The primary objective of the present invention is to provide a lineartable structure whose first and second screws are connected by aconnecting calibrating assembly, thus reducing cost and time formachining the threads.

To obtain the abovementioned objective, the linear table structure inaccordance with the present invention comprises a groove body, a firstscrew, a second screw, two sliding seats, and a connecting calibratingassembly. The connecting calibrating assembly is formed at either endthereof with a positioning portion, and the first and second screw arepositioned and connected by the connecting calibrating assembly. Theclockwise thread of the first threaded section of the first screw islocated opposite the counterclockwise thread of the second threadedsection of the second screw. Thus, by simply exchanging the direction ofthe thread of the first screw or the second screw, the sliding seats canbe adjusted to move relative to each other without processing thethreads with precision machining, thus reducing the cost and machiningtime.

The secondary objective of the present invention is to provide a lineartable structure capable of adjusting the pitch error of the slidingseats and ensuring the displacement precision of the sliding seats.

To obtain the abovementioned objective, the linear table structure inaccordance with the present invention comprises a groove body, a firstscrew, a second screw, two sliding seats, and a connecting calibratingassembly. The connecting calibrating assembly is formed at either endthereof with a positioning portion, and the first and second screwutilizes the positioning portion of the connecting calibrating assemblyto perform tension adjustment. By such arrangements, when positiondeviation of the sliding seats occurs, the first and second screws willutilize the positioning portion of the connecting calibrating assemblyto perform positioning or adjustment function, thus ensuring theprecision displacement of the sliding seat along the first and secondscrews.

The third objective of the present invention is to provide a lineartable structure capable of utilizing an assistant member share theweight of the first and second screws, thus avoiding excessiveoscillation and enabling the sliding seats to slide smoothly.

To obtain the abovementioned objective, the linear table structure inaccordance with the present invention comprises a groove body, a firstscrew, a second screw, two sliding seats, a connecting calibratingassembly, and an assistant member. The first and second screw canutilize the assistant member pivotally disposed beside the connectingcalibrating assembly to form a single support point or double supportpoints on the groove body. With the connection and support of theconnecting calibrating assembly, the first screw or the second screwutilizes the assistant member to disperse the weight supported by theconnecting calibrating assembly, thus avoiding excessive oscillation ofthe first and screw screws, ensuring the displacement stability of thesliding seats, and consequently enabling the sliding seats to slidesmoothly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side cross sectional view of a conventional linear table;

FIG. 2 is a side cross sectional view in accordance with the presentinvention of showing a linear table structure without assistant member;

FIG. 3 is a side cross sectional view in accordance with the presentinvention of showing a linear table structure with a single assistantmember;

FIG. 4 is a side cross sectional view in accordance with the presentinvention of showing a linear table structure with two assistantmembers;

FIG. 5 is an amplified view in accordance with the present invention ofshowing a part of the linear table structure;

FIG. 6 is another amplified view in accordance with the presentinvention of showing a part of the linear table structure; and

FIG. 7 is a cross sectional view in accordance with the presentinvention of showing a connecting calibrating assembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be more clear from the following descriptionwhen viewed together with the accompanying drawings, which show, forpurpose of illustrations only, the preferred embodiment in accordancewith the present invention.

Referring to FIGS. 2-7, a linear table structure in accordance with thepresent invention comprises: a groove body 20, a first screw rod 30, asecond screw rod 40, two sliding seats 50, a connecting calibratingassembly 60, and an assistant member 70.

The groove body 20 is interiorly defined with a receiving space 21.

The first screw 30 is formed on its outer surface with a first threadedsection 31, at one end of the first threaded section 31 is axiallyformed a first pivot portion 32, and at the other end of the firstthreaded section 31 is axially formed a first connecting portion 33.

The second screw 40 is formed on its outer surface with a secondthreaded section 41 whose pitch is the same as the pitch of the firstthreaded section 31 of the first screw 30, at one end of the secondthreaded section 41 is formed a second pivot portion 42, and at theother end of the second threaded section 41 is formed a secondconnecting portion 43.

Each of the sliding seats 50 includes a base 51 and two nuts 52. Thebase 51 is a rectangular board, the nuts 52 are radially fixed to thebottom of the base 51, so that the sliding seats 50 are fixed to thefirst threaded section 31 of the first screw 30 and the second threadedsection 41 of the second screw 40, respectively, by the nuts 52.

The connecting calibrating assembly 60 is a cylinder-shaped and includestwo positioning portions 61 defined at both ends of the connectingcalibrating assembly 60.

Each of the positioning portions 61 includes an inserting groove 62, apositioning hole 63, and a restricting member 64.

The inserting groove 62 is axially defined in the positioning portion 61for insertion of the first connecting portion 33 of the first screw 30and the second connecting portion 43 of the second screw 40,respectively. And then the first pivot portion 32 of the first screw 30and the second pivot portion 42 of the second screw 40 are pivotallydisposed on the inner surface of both sides of the groove body 20. Thefirst screw 30 and the second screw 40 are disposed in the receivingspace 21 of the groove body 20 in such a manner that the first threadedsection 31 of the first screw 30 is located opposite the second threadedsection 41 of the second screw 40, so that the sliding seats 50 moverelative to each other along with the rotation of the first and secondscrews 30 and 40.

The positioning hole 63 formed with inner threads is radially defined inthe outer surface of the positioning portion 61 and is in communicationwith the inserting groove 62.

The restricting member 64 formed with outer threads is pressed againstthe first connecting section 33 of the first screw 30 and the secondconnecting section 43 of the second screw 40 by screwing throughpositioning hole 64. When any one of the sliding seats 50 deviates, oneof the restricting members 64 of the connecting calibrating assembly 60can be loosened to adjust the relative position of the first threadedsection 31 of the first screw 30 or the second threaded section 41 ofthe second screw 40. After adjustment, the restricting member 64 can bescrewed in the positioning hole 64 against until it is pressed againstthe first connecting section 33 of the first screw 30 or the secondconnecting section 43 of the second screw 40. Therefore, it ensures thedisplacement precision of the sliding seats 50 without worrying that thethread positions of the nuts 52 are different.

The assistant member 70 is a bearing used to relieve the oscillationcaused by the rotation of the first screw 30 (as shown in FIGS. 3 and 4)and the second screw 40.

The assistant member 70 is pivotally mounted on the first threadedportion 31 of the screw 30 beside the first pivot connection to form asingle support point on the groove body 20.

The assistant member 70 is pivotally mounted on the second threadedportion 41 of the second screw 40 beside the second pivot portion toform another single support point on the groove body 20.

Of course, on each of the first threaded portion 31 of the screw 30 andthe second threaded portion 41 of the second screw 40 beside the firstand second pivot portions can be disposed an assistant member 70, thusforming two support points on the groove body 20. The assistant member70 not only reduces the weight supported by the connecting calibratingassembly 60 and improves the stability of rotation, but also preventsthe first screw 30 and the second screw 40 from excessive oscillation,and consequently ensuring the precision displacement of the slidingseats 50 along the first and second screws 30 and 40.

The positioning portion 61′ of a connecting calibrating assembly 60′ inaccordance with a second embodiment of the present invention is shown inFIG. 7 and includes a C-shaped retainer 62′, a pulling member 63′, apivot 64′, a screw 65′, and a nut 66′.

The C-shaped retainer 62′ is formed at either end of the connectingcalibrating assembly 60′ for insertion of the first and second screws 30and 40, respectively. One end of the pulling member 63′ is pivotallyconnected at one end of the screw 65′ by the pivot 64′, the screw 65′ isinserted through both ends of the C-shaped retainer 62′, and the pullingmember 63′ is disposed on the C-shaped retainer 62′. Both ends of theC-shaped retainer 62′ are limited by the pulling member 63′ and the nut66′, the user only needs to pull the pulling member 63′, the screw 65′will be caused to adjust the tension of the C-shaped retainer 62′, andthen the first and second screws 30 and 40 rotate to adjust thedisplacement error of the sliding seats 50.

The abovementioned linear table structure comprises the sliding seat 50moveably disposed on the first screw 30 and another sliding seat 50moveably disposed on the second screw 40, and the two sliding seats 50move relative to each other. Of course, with the function of connectionand calibration of the connecting calibrating assembly 60, the number ofthe sliding seats and the screws can be adjusted according to need, andthe number of the assistant member 70 can be adjusted according to thedegree of oscillation of the screws.

For a better understanding of the present invention, its operation andfunction, reference should be made to FIGS. 2-7 again while reading thefollowing descriptions:

A. The first screw 30 and the second screw 40 are connected through theinserting groove 62 of the connecting calibrating assembly 60, theclockwise thread of the first threaded section 31 of the first screw 30is located opposite the counterclockwise thread of the second threadedsection 41 of the second screw 40.

As mentioned above that the first screw 30 and the second screw 40 areconnected by the connecting calibrating assembly 60, by simplyexchanging the direction of the thread of the first screw 30 or thesecond screw 40, the sliding seats 50 can be adjusted to move relativeto each other without processing the threads with precision machining,thus reducing the cost and machining time.

B. The first screw 30 and the second screw 40 are connected, positionedand adjusted by the positioning portion 61 of the connecting calibratingassembly 60.

As can be seen from the above description, when position deviation ofthe sliding seats 50 occurs, the first screw 30 and the second screw 40will utilize the positioning portion 61 of the connecting calibratingassembly 60 to perform positioning or adjustment function, enabling theuser to easily adjust the pitch error caused on the first and secondscrews 30 and 40 by the sliding seats 50, thus ensuring the precisiondisplacement of the sliding seat 50 along the first and second screws 30and 40.

C. The first screw 30 or the second screw 40 can be provided with anassistant member 70 beside the connecting calibrating assembly 60 toform a single support point or a double support point on the groove body20.

With the connection of the connecting calibrating assembly 60, the firstscrew 30 or the second screw 40 utilizes the assistant member 70 todisperse the weight supported by the connecting calibrating assembly 60,thus avoiding excessive oscillation of the first and screw screws 30,40, ensuring the displacement stability of the sliding seats 50, andconsequently enabling the sliding seats 50 to slide smoothly.

To summarize, the linear table structure in accordance with the presentinvention comprises: a groove body, a first screw, a second screw, twosliding seats and a connecting calibrating assembly. The first andsecond screws are connected by the connecting calibrating assembly, theconnecting calibrating is used to adjust the pitch error generated onthe first and second screws by the sliding seats, thus reducingprocessing time and cost.

While we have shown and described various embodiments in accordance withthe present invention, it is clear to those skilled in the art thatfurther embodiments may be made without departing from the scope of thepresent invention.

1. A linear table structure comprising: a groove body defined with areceiving space; a first screw formed on its outer surface with a firstthreaded section; a second screw formed on its outer surface with asecond threaded section; two sliding seats each including a base and anut, the nut being fixed to a side of the base, so that the slidingseats are fixed to the first threaded section of the first screw and thesecond threaded section of the second screw, respectively, by the nuts;a connecting calibrating assembly being formed at each end thereof witha positioning portion, one end of the first screw and the second screware connected to the positioning portions of the connecting calibratingassembly, respectively, the other end of the first screw and the secondscrew are pivotally disposed in the receiving space of the groove body,the sliding seats utilize the positioning portion of the connectingcalibrating assembly to do tension adjustment, thus rotating the firstand second screws to adjust pitch error of the sliding seats.
 2. Thelinear table structure as claimed in claim 1, wherein the first screwfurther includes a first pivot portion and a first connecting portion,the first pivot portion is formed at one end of the first screw, and thefirst connecting portion is formed at the other end of the first screw;the second screw further includes a second pivot portion and a secondconnecting portion, the second pivot portion is formed at one end of thesecond screw, and the second connecting portion is formed at the otherend of the second screw, the first connecting portion of the first screwand the second connecting portion of the second screw are connected tothe positioning portion of the connecting calibrating assembly, thefirst pivot portion of the first screw and the second pivot portion ofthe second screw are pivotally disposed on an inner surface of bothsides of the groove body, so that the first and second screws aredisposed in the receiving space of the groove body.
 3. The linear tablestructure as claimed in claim 2, wherein the positioning portionsincludes an inserting groove, a positioning hole, and a restrictingmember; the inserting groove is axially defined in the positioningportion for insertion of the first connecting portion of the first screwand the second connecting portion of the second screw, respectively; thepositioning hole formed with inner threads is radially defined in anouter surface of the positioning portion and is in communication withthe inserting groove; and the restricting member formed with outerthreads is pressed against the first connecting section of the firstscrew and the second connecting section of the second screw by screwingthrough positioning hole.
 4. The linear table structure as claimed inclaim 3, wherein an assistant member is pivotally mounted on the firstthreaded portion of the screw and located beside the first pivotconnection to form a single support point on the groove body.
 5. Thelinear table structure as claimed in claim 3, wherein an assistantmember is pivotally mounted on the second threaded portion of the secondscrew and located beside the second pivot portion to form a singlesupport point on the groove body.
 6. The linear table structure asclaimed in claim 3, wherein an assistant member is mounted on each ofthe first threaded portion of the screw and the second threaded portionof the second screw located beside the first and second pivot portions.7. The linear table structure as claimed in claim 3 further comprisingan assistant member, and the assistant member is a bearing.
 8. Thelinear table structure as claimed in claim 3, wherein the connectingcalibrating assembly further includes a C-shaped retainer, a pullingmember, a pivot, a screw, and a nut, the C-shaped retainer is formed ateither end of the connecting calibrating assembly for insertion of thefirst and second screws, respectively, one end of the pulling member ispivotally connected at one end of the screw of the connectingcalibrating assembly by the pivot, the screw of the connectingcalibrating assembly is inserted through both ends of the C-shapedretainer, and the pulling member is disposed on the C-shaped retainer,one end of the screw of the connecting calibrating assembly is exposedout of the C-shaped retainer so as to screw with the nut, such that bothends of the C-shaped retainer are limited by the pulling member and thenut.
 9. The linear table structure as claimed in claim 8, wherein anassistant member is pivotally mounted on the first threaded portion ofthe screw and located beside the first pivot connection to form a singlesupport point on the groove body.
 10. The linear table structure asclaimed in claim 8, wherein an assistant member is pivotally mounted onthe second threaded portion of the second screw and located beside thesecond pivot portion to form a single support point on the groove body.11. The linear table structure as claimed in claim 8, wherein anassistant member is mounted on each of the first threaded portion of thescrew and the second threaded portion of the second screw located besidethe first and second pivot portions.
 12. The linear table structure asclaimed in claim 8 further comprising an assistant member, and theassistant member is a bearing.